The use of water-wettable polymer sorbents reduces or eliminates SPE column conditioning and equilibration steps, thereby saving time, reagent and labor costs.

SPEware is the expert in positive pressure processing of SPE columns. Positive pressure processing has numerous advantages compared to traditional vacuum manifold processing. Positive pressure provides consistent uniform flow across a set of columns or wells, and coupled with electronic flow control, allows for perfectly reproducible flow profiles to be embedded within methods. SPEware positive pressure processors are designed to be fully compatible and provide seamless work flow with other laboratory platforms, such as evaporators and robotic liquid handlers.

CEREX® High Efficiency Extraction SPE or Phospholipid/protein crash columns are produced from a family of polymeric sorbents. These sorbents are divided into two classes, namely, co-polymeric and functionalized polymers.

CEREX® is a patented manufacturing technology that enables creation of very high performance solid phase extraction (SPE) columns. CEREX® technology provides for the use of microparticulate sorbents in the SPE column, typically in the 10µm particle size range, as compared to the 40µm particle size range used by most commercial suppliers. Microparticulate sorbents offer tangible and significant benefits compared to larger particle sorbents; specifically, very high capture efficiency.

Capture efficiency refers to the ability of a SPE device to effectively retain, or "trap" desired analytes from the applied sample. Regardless of the chemical affinity of the sorbent for the analyte species, SPE products that use large particle sorbents may exhibit significant analyte breakthrough during sample application. This is caused by the relatively large flow paths between sorbent particles, allowing analytes to bypass contact with the sorbent (Figure 1).

In contrast, CEREX® microparticulate sorbents contain much smaller flow paths, ensuring contact with the sorbent as the analyte molecules pass through the sorbent bed. This results in more efficient and consistent analyte trapping, leading to higher analyte recoveries and more reproducible results (Figure 2).

A loading experiment demonstrates the difference between an 8µm sorbent and a conventional 40µm sorbent, using surface-matched sorbent chemistries, in an online cartridge format (graph courtesy of Spark Holland, see Figure 3). Breakthrough of a UV-absorbing analyte from each respective cartridge is measured using a conventional UV detector. The trace begins with the cartridge bypassed; therefore, the detector signal reflects the level of analyte in the loading solvent.

As the cartridge is placed into the sample stream, absorbance drops initially, and then recovers as analyte "breaks through" the cartridge. Note that the 8um cartridge captures roughly 4 times the analyte quantity as the 40µm cartridge before breakthrough, and reaches total saturation capacity immediately thereafter, as seen by rapid recovery of the detector signal to initial conditions. In contrast, the 40µm cartridge never reaches saturation capacity, even after many minutes of sample loading.

This high capture effect of micro-particles allows the use of much smaller bed masses in CEREX ® columns compared to conventional sorbents. For example, a 35mg or even a 20mg CEREX® column typically exhibits the same effective capacity as a 100mg, 40µm conventional SPE product. The use of smaller sorbent beds allows for commensurately smaller analyte elution volumes, as demonstrated in Figure 4 (chromatogram courtesy of Spark Holland).

Van Deemter: Wider Flow Range

Extractions using CEREX® columns are faster and less operator dependent than classical SPE. One of the contributing factors to this benefit is the wider usable flow range when using smaller particles. The form of the Van Deemter equation is such that HETP achieves a minimum value at a particular flow velocity (low HETP values are good). At this flow rate, the resolving power of the column is maximized. The window for this maximum performance – resolving power - broadens as particle size drops. This means a wider flow range through the bed is allowable; i.e. more rugged methods and less dependence on flow rate for performance.

PRODUCT SELECTION

CEREX® SPE products are available in a wide range of sorbent chemistries and configurations. Column formats offered include standard syringe-barrel tubes with luer-tips in the most widely used sizes (1, 3, and 6 mL tubes). In 96-well formats (including NBE), both "integrated" (single plate) and "modular" (base plate plus plug-in columns) formats are available to accommodate specific user applications. Column bed masses range from 1 mg up to 1 gram scale in the largest columns.

Different column sizes for different applications

1 mL is perfect for high throughput sample extraction, automation and automated method development

3 mL is designed for more difficult matrices such as whole blood, neat oral fluid, animal urine, etc.

6 mL is designed for even more difficult matrices such as post-mortem samples, tissues, etc.

1 mL in 96-well format is assembled to your specifications or can be assembled in your laboratory.

Designed with a gap between each well to eliminate cross contamination

Standard footprint manufactured to ISO 9001 (ANSI) specifications

Manufactured from superior quality polypropylene, deep plates can be stored in the freezer to -70° C and may be autoclaved repeatedly